Does Beer Go Bad: What Happens If You Drink Expired Beer?

Aug 2021 | Last modified: September 18, 2023 | 10 min read | By Alex Goldberg

guy hungover from drinking beer

We’ve all been there. Spring cleaning time. While throwing out old leftovers in the fridge you notice it: that craft brewed Octoberfest ale. You remember it being pretty good. But it’s been in there for six months… or maybe it was from the fall before then? And spring cleaning makes you very THIRSTY.

So what do you do? Can you drink it? What is the actual shelf life of beer? Does beer go bad? And what is that green fuzzy stuff in your Tupperware?

Don’t worry… we got you. You will soon find out if that beer is safe to drink, or will that expired beer make you sick?

Does Beer Go Bad: Will Expired Beer Make You Sick?

So can drinking expired beer make you sick?

Let’s get this one out of the way right now. No, it cannot make you sick. After beer has finished brewing and is fully fermented, harmful pathogens will not grow in beer.

This is different from other types of expired foods like meat or dairy. However, if there is contamination at a commercial brewing facility, then you can get sick. That said, when breweries experience a contamination, they will not ship the beer for distribution.

As you probably know, the most likely way you will get sick from drinking beer is by drinking too much beer in one sitting.

What Is Skunked Beer?

“Skunked beer” is the term for beer that has lost its flavor. It may taste flat, sour or have the faint smell of skunk. This can happen for a few different reasons:

  • Oxygen
  • Heat
  • Exposure to UV Rays
  • Bacteria


In each bottle, can or keg of beer, there is always a tiny amount of air. We’re talking a teeny, tiny amount, as in parts per billion. This is normal and part of the beer packaging process.

However, over time the oxygen will change the characteristics of the beer. This is known as oxidation. This will, over time, will change the flavor of the beer slightly. However, these changes are very small and may take a long time for it to be noticeable.


Heat itself will not alter the flavor of your beer. Of course, we don’t recommend you drink warm beer EVER, but know that accidentally leaving a six pack of beer in the trunk of your car for an afternoon won’t kill the flavor.

What heat will do is it speeds up the oxidation process and will, in a quicker amount of time, alter the flavor of your beer.

Exposure To UV Rays

Too much exposure to ultra-violet (UV) light is a no no. When UV rays, either from sunlight or some lights in stores, hit the bottle then some not so good things start to happen.

The molecules in the beer begin to break apart, and then a sulfuric compound is made. This creates the flavor we all certainly recognize and do not enjoy. Fortunately, there are ways to protect your beer and keep it fresher for longer.


EVERYTHING, including beer, will decay after time. Living bacteria will eat away at everything. Commercial brewers take extra precautions to minimize contamination.

Fortunately, there are two things working in beer’s favor to slow contamination: the alcohol content is a natural preservative as bacterial microbes can’t survive. Also, refrigeration slows the process as well.

By the way, what we all probably think as the likeliest way to skunk beer is a total myth: changing the temperature in a short-term situation. It has long been believed that if you take beer out of the fridge and it gets to room temperature, it is skunked and there is no point in putting it back in the fridge.

This is simply not true. If it has been exposed to excessive heat for days or weeks, then you might have a problem. Otherwise, just stick it back in the fridge and your beer will be crisp, cool, delicious, and fresh.

How Long Does Beer Last?

You have probably noticed that your beer has a “sell by” or “best by” date on the can or bottle. These dates are not the day you should throw out any unconsumed beer. These dates are what the brewmaster recommends the beer should be consumed by for the best and freshest taste.

In fact, depending on what kind of beer it is and how you store it, your beer could last for months or even years..

Aluminum Cans

When beer is packaged in aluminum cans, it is completely protected from light and oxygen. With cans, there is very little headspace between the beer and the lid, which minimizes the amount of oxygen inside of the can.

For aluminum cans, beer will last roughly six to nine months after the sell by date if you store it at room temperature. If you store it in the fridge, those cans could last up to two years.

Glass Bottles

For bottles, this will depend on the color of the glass. Remember, it’s the UV rays that can spoil beer. Brown glass bottles block almost all UV rays. Clear and green glass allow those pesky rays to enter.

Storage is key: if your bottles are kept at room temperature in a place without any direct sunlight, like a pantry or garage, then you can get six to nine months at room temperature.

If there is exposure to light, then very soon after the sell by date your beer might be skunked. Since your fridge does not have UV light beaming through the glass, your beer is safe for up to two years.

Growlers and Beer Dispensers

In growlers and beer dispensers, the freshness period is much shorter since the beer has been exposed to air.

Many breweries and taprooms will fill a growler or crowler with their beer, and allow you to take it home and drink. These are meant to be enjoyed right away and not meant for long-term storage.

But if used with a beer gun or counter-pressure filler that will use CO2 to push out the oxygen, your beer can last in a pressurized growler for two to five weeks.

However, once you open that beer, the clock is ticking: your beer will go flat within 24 to 48 hours.


Even if you keg your beer, it will only stay fresh for so long.  But depending on how you are dispensing the beer from a keg, will determine if it will last just one day or three months.

If you are using a manual pump to pressurize the keg so the beer can be dispensed, you are introducing a lot of oxygen into the keg which drastically decreases the freshness of the beer.  If you over-pump and introduce too much air, you will be drinking a lot of excessive foam.  These types of pumps are good for parties because the beer might only last one day.

However, when using a kegerator, CO2 is used to pressurize the keg and dispense the beer, avoiding oxidation because the keg will remain pressurized.  When you put your beer in a keg with this type of system, you can avoid flat tasting beer, and your beer can stay fresh for three or four months.

The Best Way To Store Beer and Keep It Fresh

The best storage place to maximize your beer shelf life is in your fridge. At a steady, constant, and cool temperature without any exposure to UV rays, your beer in the fridge can last years. There are optimal
conditions for making your beer last a while in the fridge:

Temperature: The ideal serving temperature for most styles of craft beer is around 45°F. So being able to store your beer in a temperature controlled environment, like a min-fridge is the way to go.

This applies for most beers, except for lagers such as Budweiser, Miller and Coors, which are better enjoyed when they are ice cold.

beer cans in a mini fridge

You can store beer at room temperature, provided the climate is relatively cool. A garage or pantry where the temperature is between 60 and 70 degrees can keep beers fresh for up to two years, and the lagers mentioned above will last even longer.

Light: No light = no problem. Without exposure to UV rays your beer will stay fresher longer. Obviously not a problem in the fridge, but it can be elsewhere.

A basement or a pantry that has no windows to outside are perfect, as well as a temperature range that doesn’t vary too much. Keeping your beer in a garage is not the best spot for you to store your beer.

For craft beers with higher alcohol content, they are often best stored at a temperature between 50° and 55° fahrenheit, and can last well beyond two years.

In fact, some stouts, barley wines, lambics and other unfiltered beers actually get better over a few years and you will notice a change (for the better) in the flavor profile over time. This change isn’t the beer going bad; it’s just the beer is going through an extended aging process.

Does Beer Go Bad In The Fridge?

Unfortunately all beers will eventually go bad and be undrinkable, and that includes beer in your fridge.

Keeping your beer in a cool and dark area like a dedicated beer refrigerator is the best place to store your beer and to keep it fresh as long as possible.

How To Tell If Your Beer Is Bad

There are a few different ways to tell if you have bad or skunked brew.

Most often there will be a unmistakable odor and distinct off-flavors in the beer that will be a definite indicator. Your nose is usually the best indicator if you should drink the beer or not.

Stale: if your beer has a stale taste (like cardboard) it more than likely has been oxidized.

Popcorn: If you experience a buttery taste like buttered popcorn, then you are tasting Diacetyl. This is produced in almost every beer fermentation, but you ordinarily can’t taste it. Too much of it is not only a sign that your beer has turned, but an excessive amount can be harmful for your lungs. Fortunately, it takes far more Diacetyl than exists in your beer to make you sick. Still, it’s a sign your beer is not good.

Cabbage: Unless you are cooking beer-braised cabbage, your beer should not taste like cabbage.

Sewage or sulphur: What time is it if your beer smells or tastes like sewage? It’s time to pour it down the drain.

In addition, you can use your sense of smell. If it smells like a skunk, then your beer is most likely skunked.

Can You Freeze Beer?

If you are trying to preserve your beer as long as possible, should you freeze it and drink it when it’s thawed?  Even though most beers are lower in alcohol and mostly made of water, beer will certainly freeze.

Maybe you could make some adult beer popsicles to enjoy, but drinking thawed beer that was previously frozen is probably something you don’t want to do.  Besides, it just won’t taste the same as if it was fresh,
and the beer will expand when it freezes and can cause the bottle to break.

aluminum can and frozen beer

Final Say

As you know already, beer is a magical concoction that has many benefits.

And now you know, in appropriate conditions beer will last a long time and can remain flavorful for months, if not years, after the expiration date.

Plus, you will not get sick from drinking expired beer (unless you drink too much). So go ahead and enjoy that mystery beer from the back of the fridge. And remember: responsible drinkers finish what they have before they buy their next six pack, growler, or case.


2 thoughts on “Does Beer Go Bad: What Happens If You Drink Expired Beer?”

    1. Is it a homebrewed beer or a commercially brewed beer? Some beers actually get better after aging for a while, but most beer will always taste better when they are fresh. Many beers will start to lose the aroma, flavor, and carbonation after a period of time. You can always use the eye and nose test. If it smells and looks bad, get rid of it. If it seems like it would be something you would still drink, go ahead and try it. With that said, a beer that has expired shouldn’t make you sick, but it’s up to you if you want to use it or not.


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